CN114606461B - Preparation method of Al-Ti-C-N nanocrystalline and application of Al-Ti-C-N nanocrystalline in aluminum alloy - Google Patents

Abstract

The invention discloses a preparation method of Al-Ti-C-N nanocrystalline and application thereof in aluminum alloy, which comprises the following steps: (1) mounting of substrate material: mounting a substrate material on a clamp, and placing the substrate material in a vacuum coating chamber; (2) pretreatment: starting a vacuum pumping system, a heating system and a mechanical transmission system in sequence, vacuumizing and heating a vacuum chamber, then filling high-purity argon, starting pulse bias voltage, and performing discharge cleaning; (3) multi-arc ion plating: and (3) filling reaction gas, setting a target material, opening an arc source, setting parameters, and then performing coating to obtain the Al-Ti-C-N nanocrystal. The invention adopts the arc ion plating method to prepare the nano-sized AlTiCN grain refiner, and the prepared refiner can refine grains containing Zr aluminum alloy and Si aluminum alloy, thereby overcoming Zr poisoning and silicon poisoning in grain refinement.

Description

A kind of preparation method of Al-Ti-C-N nanocrystal and its application in aluminum alloy

technical field

The invention relates to the field of aluminum alloy materials, in particular to a method for preparing Al-Ti-C-N nanocrystals and their application in aluminum alloys.

Background technique

Aluminum alloy has the advantages of high specific strength and rigidity, good corrosion resistance, etc., and is widely used in aerospace, rail transit, automobile, electronic communication and other fields. In particular, heat-treatable and strengthened ultra-high-strength 7XXX aluminum alloys, after undergoing large plastic deformation and heat treatment, can have a tensile strength of over 900MPa, making them an ideal aerospace material. Adding a certain amount of Zr and Sc to the 7XXX alloy can form ZrAl ₃ and ScAl ₃ particles with high thermal stability and micro-nano size, which can effectively inhibit the grain growth during heat treatment and significantly improve the overall performance of the alloy, such as 7050, 7075 and other alloys. Since the price of Sc is much higher than that of Zr, Zr becomes the most commonly used element to inhibit grain growth. However, the study found that there is a phenomenon of "refinement poisoning" between Zr and Al-Ti-B refiners, that is, when the two are added at the same time, the refinement effect is significantly weakened compared with that added alone. The reason is not clear, the possible elements include Zr replacing Ti to form ZrB ₂ , the presence of Zr affects the formation of Al ₃ Ti and destroys the heterogeneous nucleation process of Al-Ti-B.

In order to solve the problem of grain refinement of Zr-containing ultra-high-strength aluminum alloys, refiners with resistance to "Zr poisoning" have been developed at home and abroad, including micro-nano-sized aluminum titanium carbon nitrogen (Al-Ti-C-N). The publication number is CN106319263A, which discloses an aluminum carbonitride titanium aluminum alloy grain refiner and its preparation method, mainly including: preparation of aluminum titanium carbon nitrogen prefabricated block, pressing the prefabricated block into aluminum melt for melting, casting and other steps , the prepared AlTiCN not only has good grain refinement ability, but also can further improve the comprehensive mechanical properties of aluminum alloy. However, long-time high-temperature ball milling is involved in the preparation of the preform, resulting in low production efficiency and high cost of aluminum titanium carbonitride.

CN108149127B discloses a kind of aluminum-based nano-titanium carbonitride seed crystal alloy and preparation method thereof, the method is through mixing (aluminum powder, titanium nitride powder, graphene are carried out dry treatment), degassing sheath, vacuum heating (vacuum 1×10 ^-3 ~ 5×10 ^-3 Pa, heating temperature), melt reaction and other steps to prepare an aluminum-based nano-titanium carbonitride seed crystal alloy. The preparation process is relatively complicated, and the reaction is stable and high.

CN106435541B discloses a titanium carbonitride-based aluminum alloy grain refiner and a preparation method thereof. The method coats a layer of nano-sized Cu on the surface of titanium carbonitride through coarsening, sensitization and activation, which significantly improves the It solves the problem of poor wettability between heterogeneous nucleation particles and aluminum liquid, improves the uniform dispersion of titanium carbonitride particles in aluminum liquid, and obtains better grain refinement effect. However, a certain amount of Cu may be introduced into the alloy, and the preparation process is relatively complicated.

CN109439952B and CN109576525A disclose a preparation method of micro-nano hybrid-scale multiphase ceramic particles and their application in 7075 aluminum alloy rolled plates. Nano-hybrid-scale heterogeneous ceramic particles were added to 7075 alloy to prepare high-performance aluminum alloy plates. But the preparation process is long and complicated.

Contents of the invention

Aiming at the problems existing in the prior art, the object of the present invention is to provide a method for preparing Al-Ti-C-N nanocrystals and their application in aluminum alloys.

The object of the present invention adopts following technical scheme to realize:

In a first aspect, the present invention provides a method for preparing Al-Ti-C-N nanocrystals, comprising the following steps:

(1) Installation of the substrate material: install the substrate material on the fixture and place it in the vacuum coating chamber;

(2) Pretreatment: turn on the vacuum system, heating system and mechanical transmission system in sequence, vacuumize the vacuum chamber and heat up, then fill it with high-purity argon, turn on the pulse bias voltage, and discharge cleaning;

(3) Multi-arc ion plating: fill in the reaction gas, set the target, turn on the arc source, set the parameters and perform coating to obtain Al-Ti-C-N nanocrystals.

Preferably, in the step (1), the clamp is capable of self-rotation and revolution.

Preferably, in the step (2), the pressure of the vacuum chamber is evacuated to 1˜5×10 ⁻³ Pa, and the temperature of the vacuum chamber is 100˜200° C.

Preferably, in the step (2), the argon pressure is adjusted to 1-5 Pa after filling with high-purity argon.

Preferably, in the step (2), after turning on the pulse bias voltage, adjust the duty ratio to 10-30%, the bias voltage to -600--1500V, and discharge cleaning for 1-3 minutes.

Preferably, in the step (3), before charging the reaction gas, adjust the argon pressure to 1-3×10 ^-1 Pa; after charging the reaction gas, adjust the pressure to 5-9×10 ^-1 Pa.

Preferably, in the step (3), the duty ratio of the bias voltage is 30-60%, the bias voltage is -600--2000V, the arc current is 60-120A, and the coating time is 15-120min.

Preferably, in the step (3), the target material is at least one of a pure titanium target and a titanium aluminum target with a purity of more than 95.0%.

More preferably, the mass fraction of metal titanium in the titanium-aluminum target is 5-50%.

Preferably, in the step (3), the reaction gas is a mixed gas of C ₂ H ₂ and N ₂ .

Preferably, in the step (3), the substrate is one or both of aluminum foam and aluminum foil rolls with a large specific surface area.

Preferably, in the step (3), during the multi-arc ion plating process, the two ends of the aluminum foil are fixed on different rotating shafts and rotate along the radius of the fixture to realize coil plating of the aluminum foil.

In the second aspect, the present invention provides an application of Al-Ti-C-N nano-crystals in aluminum alloy materials.

Preferably, the aluminum alloy material is Al-0.15Zr alloy.

Preferably, the mass percentage of the Al-Ti-C-N nanocrystals added to the aluminum alloy material is 0.01%-0.1%.

The beneficial effects of the present invention are:

The present invention adopts the method of arc ion plating to prepare nano-sized AlTiCN grain refiner, and the prepared refiner can refine the grains of Zr-containing aluminum alloy and the grain of Si-containing aluminum alloy, thereby Overcome "Zr poisoning" and "silicon poisoning" in grain refinement.

In the present invention, pure titanium or aluminum titanium is used as the target material, and the target is ionized into titanium ions by arc discharge, and together with the carbon and nitrogen ions ionized by reaction gases such as _C2H2 and _{N2 ,} the bias power supply Bombard the sinking material, form nano-grains with the substrate material Al and deposit on the surface of the substrate material, by adjusting parameters such as arc parameters, target quantity and shape, bias power supply parameters, reaction gas flow rate, ion plating temperature and time, etc. , control the grain size and thickness of the coating. The composition of the coating mainly includes four elements such as Al, Ti, N, and C, the grain size ranges from 30 to 400 nm, and the thickness of the coating is 1 to 10 μm. Adding 0.1-0.2% of the refining agent to the aluminum alloy containing Zr and Si can achieve a good refining effect and overcome the poisoning effect of the Al-Ti-B refining agent. Therefore, the method for preparing nano-scale grain refiner by multi-arc ion plating technology in this application has the advantages of short process flow, easy realization of automatic coil plating, high preparation efficiency and low cost, and has good application prospects.

Description of drawings

The present invention is further described by using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. For those of ordinary skill in the art, without paying creative work, other embodiments can also be obtained according to the following accompanying drawings Attached picture.

Fig. 1 is the Al-TiCN scanning electron micrograph collection of embodiment 1 preparation;

Fig. 2 is the Al-TiCN energy spectrum that embodiment 1 prepares;

Fig. 3 is the macroscopic metallographic phase of the ingot prepared in comparative example 1;

Fig. 4 is the macroscopic metallographic phase of the ingot prepared in Example 1.

Detailed ways

In order to illustrate the present invention more clearly and have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solutions of the present invention are now described in detail below, but it cannot be interpreted as limiting the scope of the present invention.

The multi-arc ion plating of the present invention utilizes the arc discharge generated between the cathode target material and the anode vacuum coating chamber housing to evaporate and ionize the metal on the target material, form plasma with the gas in space, and deposit on the A surface coating method on sinking bottom materials. Compared with other vacuum coating technologies, it has the characteristics of high metal ionization rate, fast deposition speed, good bonding force with substrate materials, wide range of coating materials and suitable substrates, and low cost.

Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial channels, or can be obtained by existing known methods.

The present invention is further described in conjunction with the following examples.

Example 1

A preparation method of an alloy material added with Al-Ti-C-N nanocrystals, comprising the following steps:

(1) Install the through-hole foam aluminum plate on the fixture that can rotate and revolve, and place it in the vacuum coating chamber;

(2) Turn on the vacuum system, the heating system and the mechanical transmission system in sequence, pump the air pressure of the vacuum chamber to 2.5×10 ^-3 Pa, and raise the room temperature to 150°C. Then fill it with high-purity argon, and adjust the argon pressure to 5Pa; turn on the pulse bias, and adjust the duty cycle to 30%, the bias to -1000V, and discharge cleaning for 1min;

(3) Adjust the argon pressure to 2×10 ^-1 Pa, fill in the reaction gas C ₂ H ₂ and N ₂ at the same time, and adjust the pressure of the vacuum chamber to 6×10 ^-1 Pa;

(4) Using titanium with a purity of 99.0% as the target material, turn on the arc source, adjust the arc current to 80A; adjust the bias duty cycle to 45%, the bias voltage to -1200V, and the coating time to 30 minutes.

(5) The obtained refining agent is added to the Al-0.15Zr alloy at a mass ratio of 0.05%, and gravity casting is carried out to obtain an ingot.

Example 2

A preparation method of an alloy material added with Al-Ti-C-N nanocrystals, comprising the following steps:

(1) Install the roll-shaped aluminum foil on a fixture that can rotate and revolve, and place it in a vacuum coating chamber;

(2) Turn on the vacuum system, the heating system and the mechanical transmission system in sequence, pump the air pressure of the vacuum chamber to 3×10 ^{- 3} Pa, and raise the room temperature to 100°C. Then fill it with high-purity argon, and adjust the argon pressure to 3Pa; turn on the pulse bias voltage, and adjust the duty cycle to 20%, the bias voltage to -800V, and discharge cleaning for 3 minutes;

(3) Adjust the argon pressure to 3×10 ^-1 Pa, fill in the reaction gas C ₂ H ₂ and N ₂ at the same time, and adjust the pressure of the vacuum chamber to 6×10 ^-1 Pa;

(4) Using the Ti-30Al master alloy with a purity of 95.0% as the target material, turn on the arc source, adjust the arc current to 100A; adjust the bias duty cycle to 60%, the bias voltage to -2000V, and the coating time to 120min.

(5) The obtained refining agent is added to the Al-0.15Zr alloy at a mass ratio of 0.08%, and gravity casting is carried out to obtain an ingot.

Example 3

A preparation method of an alloy material added with Al-Ti-C-N nanocrystals, comprising the following steps:

(1) Install the through-hole foam aluminum plate on the fixture that can rotate and revolve, and place it in the vacuum coating chamber;

(2) Turn on the vacuum system, the heating system and the mechanical transmission system in sequence, pump the air pressure of the vacuum chamber to 1×10 ^{- 3} Pa, and raise the room temperature to 200°C. Then fill it with high-purity argon, and adjust the argon pressure to 1Pa; turn on the pulse bias voltage, and adjust the duty cycle to 30%, the bias voltage to -600V, and discharge cleaning for 2 minutes;

(3) Adjust the argon pressure to 2×10 ^-1 Pa, fill in the reaction gas C ₂ H ₂ and N ₂ at the same time, and adjust the pressure of the vacuum chamber to 9×10 ^-1 Pa;

(4) Using the Ti-10Al master alloy with a purity of 98.0% as the target material, turn on the arc source, adjust the arc current to 60A; adjust the bias duty cycle to 40%, the bias voltage to -800V, and the coating time to 90min.

(5) The obtained refiner is added to the Al-0.15Zr alloy at a mass ratio of 0.1%, and gravity casting is carried out to obtain an ingot.

Example 4

A preparation method of an alloy material added with Al-Ti-C-N nanocrystals, comprising the following steps:

(1) Install the through-hole foam aluminum plate on the fixture that can rotate and revolve, and place it in the vacuum coating chamber;

(2) Turn on the vacuum system, the heating system and the mechanical transmission system in sequence, pump the air pressure of the vacuum chamber to 2×10 ^{- 3} Pa, and increase the room temperature to 120°C. Then fill it with high-purity argon, and adjust the argon pressure to 3Pa; turn on the pulse bias, and adjust the duty cycle to 20%, the bias to -900V, and discharge cleaning for 1min;

(3) Adjust the argon pressure to 1.5×10 ^-1 Pa, fill in the reaction gas C ₂ H ₂ and N ₂ at the same time, adjust the vacuum chamber pressure to 8×10 ^-1 Pa;

(4) Using titanium with a purity of 99.0% as the target material, turn on the arc source, adjust the arc current to 90A; adjust the bias duty cycle to 50%, the bias voltage to -1100V, and the coating time to 60min.

(5) The obtained refining agent is added to the Al-0.15Zr alloy in a mass ratio of 0.03%, and gravity casting is carried out to obtain an ingot.

Comparative example 1

An alloy material is an Al-0.15Zr alloy gravity casting ingot without adding any refiner.

Experimental example

Choose the ingot that embodiment 1～4 and comparative example 1 provide, test the average grain size of alloy, the result is as follows table 1:

Table 1 Average grain size of cast ingot

serial number Example 1 Comparative example 1 Example 2 Example 3 Example 4 Average Grain Diameter (μm) 140 450 115 130 180

It can be seen from the above table 1 that the ingots added with the Al-Ti-C-N nanocrystalline refiner prepared in Examples 1 to 4 of the present invention have smaller grain diameters, especially in Example 2 at a ratio of 0.08%. The added one has the smallest grain diameter, which can explain that the Al-Ti-CN coating has a good anti-Zr and Si poisoning effect, and the grains are significantly refined.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand , the technical solution of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims (1)

1. A preparation method of Al-Ti-C-N nanocrystals is characterized by comprising the following steps:

(1) Mounting of substrate material: mounting a substrate material on a clamp, and placing the substrate material in a vacuum coating chamber;

(2) Pretreatment: starting a vacuum pumping system, a heating system and a mechanical transmission system in sequence, vacuumizing and heating a vacuum chamber, then filling high-purity argon, starting pulse bias voltage, and performing discharge cleaning;

(3) Multi-arc ion plating: filling reaction gas, setting a target material, opening an arc source, setting parameters, and then performing film coating to obtain Al-Ti-C-N nanocrystals;

in the step (3), the target material is at least one of a pure titanium target and a titanium-aluminum target with the purity of more than 95.0%;

in the step (3), the reaction gas is C ₂ H ₂ And N ₂ Mixed gas of (2), C ₂ H ₂ And N ₂ Is 10;

in the step (3), the substrate is one or two of foamed aluminum and an aluminum foil roll;

the Al-Ti-C-N nanocrystalline is used as a grain refiner of the aluminum alloy material;

in the step (2), the air pressure of the vacuum chamber is pumped to 1-5 multiplied by 10 ^-3 Pa, the temperature of the vacuum chamber is 100-200 ℃; filling high-purity argon, and adjusting the argon pressure to 1-5 Pa;

in the step (2), after the pulse bias voltage is started, the duty ratio is adjusted to be 10-30%, the bias voltage is-600V to-1500V, and the discharge cleaning is carried out for 1-3 min;

in the step (3), before the reaction gas is filled, the pressure of the argon gas is adjusted to 1-3 multiplied by 10 ^-1 Pa; after reaction gas is filled, the gas pressure is adjusted to 5-9X 10 ^-1 Pa；

In the step (3), the pulse bias sets the bias duty ratio to be 30-60%, the bias is-600V-2000V, the arc current is 60-120A, and the coating time is 15-120 min;

in the step (3), in the multi-arc ion plating process, two ends of the aluminum foil are fixed on different rotating shafts and rotate along the radius of the clamp to realize coil plating of the aluminum foil;

the Al-Ti-C-N nanocrystalline is applied to an aluminum alloy material.

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